Description

COPY moves data between Greenplum Database tables and standard file-system
files. COPY TO copies the contents of a table to a file (or multiple files
based on the segment ID if copying ON SEGMENT), while COPY
FROM copies data from a file to a table (appending the data to whatever is in the
table already). COPY TO can also copy the results of a
SELECT query.

If a list of columns is specified, COPY will only copy the data in the
specified columns to or from the file. If there are any columns in the table that are not in
the column list, COPY FROM will insert the default values for those
columns.

COPY with a file name instructs the Greenplum Database master host to
directly read from or write to a file. The file must be accessible to the master host and
the name must be specified from the viewpoint of the master host.

When COPY is used with the ON SEGMENT clause, the
COPY TO causes segments to create individual segment-oriented files,
which remain on the segment hosts. The filename argument for ON
SEGMENT takes the string literal <SEGID> (required) and uses
either the absolute path or the <SEG_DATA_DIR> string literal. When the
COPY operation is run, the segment IDs and the paths of the segment data
directories are substituted for the string literal values.

Using COPY TO with a replicated table (DISTRIBUTED
REPLICATED) as source creates a file with rows from a single segment so that the
target file contains no duplicate rows. Using COPY TO with the ON
SEGMENT clause with a replicated table as source creates target files on segment
hosts containing all table rows.

The ON SEGMENT clause allows you to copy table data to files on segment
hosts for use in operations such as migrating data between clusters or performing a backup.
Segment data created by the ON SEGMENT clause can be restored by tools such
as gpfdist, which is useful for high speed data loading.

Warning: Use of the ON SEGMENT clause is recommended for expert
users only.

When PROGRAM is specified, the server executes the given command and reads
from the standard output of the program, or writes to the standard input of the program. The
command must be specified from the viewpoint of the server, and be executable by the gpadmin
user.

When STDIN or STDOUT is specified, data is transmitted
via the connection between the client and the master. STDIN and
STDOUT cannot be used with the ON SEGMENT clause.

If SEGMENT REJECT LIMIT is used, then a COPY FROM
operation will operate in single row error isolation mode. In this release, single row error
isolation mode only applies to rows in the input file with format errors — for example,
extra or missing attributes, attributes of a wrong data type, or invalid client encoding
sequences. Constraint errors such as violation of a NOT NULL,
CHECK, or UNIQUE constraint will still be handled in
'all-or-nothing' input mode. The user can specify the number of error rows acceptable (on a
per-segment basis), after which the entire COPY FROM operation will be
aborted and no rows will be loaded. The count of error rows is per-segment, not per entire
load operation. If the per-segment reject limit is not reached, then all rows not containing
an error will be loaded and any error rows discarded. To keep error rows for further
examination, specify the LOG ERRORS clause to capture error log
information. The error information and the row is stored internally in Greenplum
Database.

Outputs

On successful completion, a COPY command returns a command tag of the
form, where count is the number of rows copied:

COPY count

If running a COPY FROM command in single row error isolation mode, the
following notice message will be returned if any rows were not loaded due to format
errors, where count is the number of rows rejected:

NOTICE: Rejected count badly formatted rows.

Parameters

table_name

The name (optionally schema-qualified) of an existing table.

column_name

An optional list of columns to be copied. If no column list is specified, all columns
of the table will be copied.

When copying in text format, the default, a row of data in a column of type
bytea can be up to 256MB.

query

A SELECT or VALUES command whose results are to be
copied. Note that parentheses are required around the query.

filename

The path name of the input or output file. An input file name can be
an absolute or relative path, but an output file name must be an absolute
path. Windows users might need to use an E'' string and
double any backslashes used in the path name.

PROGRAM 'command'

Specify a command to execute. In COPY FROM, the input is
read from standard output of the command, and in COPY TO,
the output is written to the standard input of the command. The command must be specified from
the viewpoint of the Greenplum Database master host system, and must be executable by
the Greenplum Database administrator user (gpadmin).

The command is invoked by a shell. When passing arguments to the
shell, strip or escape any special characters that have a special meaning for the shell.
For security reasons, it is best to use a fixed command string, or at least avoid
passing any user input in the string.

When ON SEGMENT is specified, the command must be executable on all
Greenplum Database primary segment hosts by the Greenplum Database administrator user
(gpadmin). The command is executed by each Greenplum segment
instance. The <SEGID> is required in the
command.

See the ON SEGMENT clause for information about command syntax
requirements and the data that is copied when the clause is specified.

STDIN

Specifies that input comes from the client application. The ON
SEGMENT clause is not supported with STDIN.

STDOUT

Specifies that output goes to the client application. The ON SEGMENT
clause is not supported with STDOUT.

boolean

Specifies whether the selected option should be turned on or off. You can write
TRUE, ON, or 1 to enable the
option, and FALSE, OFF, or 0 to
disable it. The boolean value can also be omitted, in which case TRUE
is assumed.

FORMAT

Selects the data format to be read or written: text,
csv (Comma Separated Values), or binary. The default
is text.

OIDS

Specifies copying the OID for each row. (An error is raised if OIDS is specified for a
table that does not have OIDs, or in the case of copying a query.)

FREEZE

Requests copying the data with rows already frozen, just as they would be after
running the VACUUM FREEZE command. This is intended as a performance
option for initial data loading. Rows will be frozen only if the table being loaded has
been created or truncated in the current subtransaction, there are no cursors open, and
there are no older snapshots held by this transaction.

Note that all other sessions will immediately be able to see the data once it has
been successfully loaded. This violates the normal rules of MVCC visibility and users
specifying this option should be aware of the potential problems this might cause.

DELIMITER

Specifies the character that separates columns within each row (line) of the file. The
default is a tab character in text format, a comma in
CSV format. This must be a single one-byte character. This option is
not allowed when using binary format.

NULL

Specifies the string that represents a null value. The default is \N
(backslash-N) in text format, and an unquoted empty string in
CSV format. You might prefer an empty string even in
text format for cases where you don't want to distinguish nulls from
empty strings. This option is not allowed when using binary
format.

Note: When using COPY FROM, any data item that matches this
string will be stored as a null value, so you should make sure that you use the same
string as you used with COPY TO.

HEADER

Specifies that a file contains a header line with the names of each column in the
file. On output, the first line contains the column names from the table, and on input,
the first line is ignored. This option is allowed only when using CSV
format.

QUOTE

Specifies the quoting character to be used when a data value is quoted. The default is
double-quote. This must be a single one-byte character. This option is allowed only when
using CSV format.

ESCAPE

Specifies the character that should appear before a data character that matches the
QUOTE value. The default is the same as the QUOTE
value (so that the quoting character is doubled if it appears in the data). This must be
a single one-byte character. This option is allowed only when using CSV
format.

FORCE_QUOTE

Forces quoting to be used for all non-NULL values in each specified
column. NULL output is never quoted. If * is
specified, non-NULL values will be quoted in all columns. This option
is allowed only in COPY TO, and only when using CSV
format.

FORCE_NOT_NULL

Do not match the specified columns' values against the null string. In the default
case where the null string is empty, this means that empty values will be read as
zero-length strings rather than nulls, even when they are not quoted. This option is
allowed only in COPY FROM, and only when using CSV
format.

ENCODING

Specifies that the file is encoded in the encoding_name. If this
option is omitted, the current client encoding is used. See the Notes below for more
details.

ON SEGMENT

Specify individual, segment data files on the segment hosts. Each file contains the
table data that is managed by the primary segment instance. For example, when copying
data to files from a table with a COPY TO...ON SEGMENT command, the
command creates a file on the segment host for each segment instance on the host. Each
file contains the table data that is managed by the segment instance.

The COPY command does not copy data from or to mirror segment
instances and segment data files.

The keywords STDIN and STDOUT are not supported with
ON SEGMENT.

The <SEG_DATA_DIR> and <SEGID> string literals
are used to specify an absolute path and file name with the following syntax:

The string literal representing the absolute path of the segment instance data
directory for ON SEGMENT copying. The angle brackets
(< and >) are part of the string literal
used to specify the path. COPY replaces the string literal with
the segment path(s) when COPY is run. An absolute path can be
used in place of the <SEG_DATA_DIR> string literal.

<SEGID>

The string literal representing the content ID number of the segment instance to
be copied when copying ON SEGMENT. <SEGID> is
a required part of the file name when ON SEGMENT is specified.
The angle brackets are part of the string literal used to specify the file name.

With COPY TO, the string literal is replaced by the content ID
of the segment instance when the COPY command is run.

With COPY FROM, specify the segment instance content ID in the
name of the file and place that file on the segment instance host. There must be a
file for each primary segment instance on each host. When the COPY
FROM command is run, the data is copied from the file to the segment
instance.

When the PROGRAM command clause is specified, the
<SEGID> string literal is required in the
command, the <SEG_DATA_DIR> string literal is
optional. See Examples.

For a COPY FROM...ON SEGMENT command, the table distribution policy
is checked when data is copied into the table. By default, an error is returned if a
data row violates the table distribution policy. You can disable the distribution policy
check with the server configuration parameter
gp_enable_segment_copy_checking. See Notes.

NEWLINE

Specifies the newline used in your data files — LF (Line feed, 0x0A),
CR (Carriage return, 0x0D), or CRLF (Carriage return
plus line feed, 0x0D 0x0A). If not specified, a Greenplum Database segment will detect
the newline type by looking at the first row of data it receives and using the first
newline type encountered.

In COPY FROM more for both TEXT and
CSV, specifying FILL MISSING FIELDS will set missing
trailing field values to NULL (instead of reporting an error) when a
row of data has missing data fields at the end of a line or row. Blank rows, fields with
a NOT NULL constraint, and trailing delimiters on a line will still
report an error.

LOG ERRORS

This is an optional clause that can precede a SEGMENT REJECT LIMIT
clause to capture error log information about rows with formatting errors.

See Notes for information about the error log
information and built-in functions for viewing and managing error log information.

SEGMENT REJECT LIMIT count [ROWS | PERCENT]

Runs a COPY FROM operation in single row error isolation mode. If the
input rows have format errors they will be discarded provided that the reject limit
count is not reached on any Greenplum Database segment instance during the load
operation. The reject limit count can be specified as number of rows (the default) or
percentage of total rows (1-100). If PERCENT is used, each segment
starts calculating the bad row percentage only after the number of rows specified by the
parameter gp_reject_percent_threshold has been processed. The default
for gp_reject_percent_threshold is 300 rows. Constraint errors such as
violation of a NOT NULL, CHECK, or
UNIQUE constraint will still be handled in 'all-or-nothing' input
mode. If the limit is not reached, all good rows will be loaded and any error rows
discarded.

Note: Greenplum Database limits the initial number of rows that can contain formatting
errors if the SEGMENT REJECT LIMIT is not triggered first or is not
specified. If the first 1000 rows are rejected, the COPY operation is
stopped and rolled back.

The limit for the number of initial rejected rows can be
changed with the Greenplum Database server configuration parameter
gp_initial_bad_row_limit. See Server Configuration Parameters for information about the
parameter.

IGNORE EXTERNAL PARTITIONS

When copying data from partitioned tables, data are not copied from leaf child
partitions that are external tables. A message is added to the log file when data are
not copied.

If this clause is not specified and Greenplum Database attempts to copy data from a
leaf child partition that is an external table, an error is returned.

See the next section "Notes" for information about specifying an SQL query to copy
data from leaf child partitions that are external tables.

Notes

COPY can only be used with tables, not with external tables or views.
However, you can write COPY (SELECT * FROM viewname) TO ...

COPY only deals with the specific table named; it does not copy data to or
from child tables. Thus for example COPY table TO shows
the same data as SELECT * FROM ONLY table. But
COPY (SELECT * FROM table) TO ... can be used to dump
all of the data in an inheritance hierarchy.

Similarly, to copy data from a partitioned table with a leaf child partition that is an
external table, use an SQL query to select the data to copy. For example, if the table
my_sales contains a leaf child partition that is an external table, this
command COPY my_sales TO stdout returns an error. This command sends the
data to
stdout:

COPY (SELECT * from my_sales ) TO stdout

The BINARY keyword causes all data to be stored/read as binary format
rather than as text. It is somewhat faster than the normal text mode, but a binary-format
file is less portable across machine architectures and Greenplum Database versions. Also,
you cannot run COPY FROM in single row error isolation mode if the data is
in binary format.

You must have SELECT privilege on the table whose values are read by
COPY TO, and INSERT privilege on the table into which
values are inserted by COPY FROM. It is sufficient to have column
privileges on the columns listed in the command.

Files named in a COPY command are read or written directly by the database
server, not by the client application. Therefore, they must reside on or be accessible to
the Greenplum Database master host machine, not the client. They must be accessible to and
readable or writable by the Greenplum Database system user (the user ID the server runs as),
not the client. Only database superusers are permitted to name files with
COPY, because this allows reading or writing any file that the server has
privileges to access.

COPY FROM will invoke any triggers and check constraints on the
destination table. However, it will not invoke rewrite rules. Note that in this release,
violations of constraints are not evaluated for single row error isolation mode.

COPY input and output is affected by DateStyle. To ensure
portability to other Greenplum Database installations that might use non-default
DateStyle settings, DateStyle should be set to ISO
before using COPY TO. It is also a good idea to avoid dumping data with
IntervalStyle set to sql_standard, because negative
interval values might be misinterpreted by a server that has a different setting for
IntervalStyle.

Input data is interpreted according to ENCODING option or the current
client encoding, and output data is encoded in ENCODING or the current
client encoding, even if the data does not pass through the client but is read from or
written to a file directly by the server.

When copying XML data from a file in text mode, the server configuration parameter
xmloption
affects the validation of the XML data that is copied. If the value is
content (the default), XML data is validated as an XML content fragment.
If the parameter value is document, XML data is validated as an XML
document. If the XML data is not valid, COPY returns an error.

By default, COPY stops operation at the first error. This should not lead
to problems in the event of a COPY TO, but the target table will already
have received earlier rows in a COPY FROM. These rows will not be visible
or accessible, but they still occupy disk space. This may amount to a considerable amount of
wasted disk space if the failure happened well into a large COPY FROM
operation. You may wish to invoke VACUUM to recover the wasted space.
Another option would be to use single row error isolation mode to filter out error rows
while still loading good rows.

When a COPY FROM...ON SEGMENT command is run, the server configuration
parameter gp_enable_segment_copy_checking controls whether the table
distribution policy (from the table DISTRIBUTED clause) is checked when
data is copied into the table. The default is to check the distribution policy. An error is
returned if the row of data violates the distribution policy for the segment instance. For
information about the parameter, see Server Configuration Parameters.

Data from a table that is generated by a COPY TO...ON SEGMENT command can
be used to restore table data with COPY FROM...ON SEGMENT. However, data
restored to the segments is distributed according to the table distribution policy at the
time the files were generated with the COPY TO command. The
COPY command might return table distribution policy errors, if you
attempt to restore table data and the table distribution policy was changed after the
COPY FROM...ON SEGMENT was run.

Note: If you run COPY FROM...ON SEGMENT and the server configuration
parameter gp_enable_segment_copy_checking is false, manual
redistribution of table data might be required. See the ALTER TABLE clause
WITH REORGANIZE.

When you specify the LOG ERRORS clause, Greenplum Database captures errors
that occur while reading the external table data. You can view and manage the captured error
log data.

Use the built-in SQL function
gp_read_error_log('table_name'). It requires
SELECT privilege on table_name. This example
displays the error log information for data loaded into table
ext_expenses with a COPY
command:

If error log data exists for the specified table, the new error log data is appended to
existing error log data. The error log information is not replicated to mirror
segments.

Use the built-in SQL function
gp_truncate_error_log('table_name') to delete the
error log data for table_name. It requires the table owner privilege
This example deletes the error log information captured when moving data into the table
ext_expenses:

SELECT gp_truncate_error_log('ext_expenses');

The
function returns FALSE if table_name does not
exist.

Specify the * wildcard character to delete error log
information for existing tables in the current database. Specify the string
*.* to delete all database error log information, including error log
information that was not deleted due to previous database issues. If * is specified,
database owner privilege is required. If *.* is specified, operating
system super-user privilege is required.

When a Greenplum Database user who is not a superuser runs a COPY command,
the command can be controlled by a resource queue. The resource queue must be configured
with the ACTIVE_STATEMENTS parameter that specifies a maximum limit on the
number of queries that can be executed by roles assigned to that queue. Greenplum Database
does not apply a cost value or memory value to a COPY command, resource
queues with only cost or memory limits do not affect the running of COPY
commands.

A non-superuser can run only these types of COPY commands:

COPY FROM command where the source is stdin

COPY TO command where the destination is stdout

For information about resource queues, see "Resource Management with Resource Queues" in
the Greenplum Database Administrator Guide.

File Formats

File formats supported by COPY.

Text Format

When the text format is used, the data read or written is a text file
with one line per table row. Columns in a row are separated by the
delimiter_character (tab by default). The column values themselves
are strings generated by the output function, or acceptable to the input function, of each
attribute's data type. The specified null string is used in place of columns that are
null. COPY FROM will raise an error if any line of the input file
contains more or fewer columns than are expected. If OIDS is specified,
the OID is read or written as the first column, preceding the user data columns.

The data file has two reserved characters that have special meaning to
COPY:

The designated delimiter character (tab by default), which is used to
separate fields in the data file.

A UNIX-style line feed (\n or 0x0a),
which is used to designate a new row in the data file. It is strongly recommended that
applications generating COPY data convert data line feeds to UNIX-style
line feeds rather than Microsoft Windows style carriage return line feeds
(\r\n or 0x0a 0x0d).

If your data contains either of these characters, you must escape the character so
COPY treats it as data and not as a field separator or new row.

By default, the escape character is a \ (backslash) for text-formatted files and a
" (double quote) for csv-formatted files. If you want to use a
different escape character, you can do so using the ESCAPE AS clause.
Make sure to choose an escape character that is not used anywhere in your data file as an
actual data value. You can also disable escaping in text-formatted files by using
ESCAPE 'OFF'.

For example, suppose you have a table with three columns and you want to load the
following three fields using COPY.

percentage sign = %

vertical bar = |

backslash = \

Your designated delimiter_character is | (pipe
character), and your designated escape character is *
(asterisk). The formatted row in your data file would look like this:

percentage sign = % | vertical bar = *| | backslash = \

Notice how the pipe character that is part of the data has been escaped using the
asterisk character (*). Also notice that we do not need to escape the backslash since we
are using an alternative escape character.

The following characters must be preceded by the escape character if they appear as part
of a column value: the escape character itself, newline, carriage return, and the current
delimiter character. You can specify a different escape character using the ESCAPE
AS clause.

CSV Format

This format option is used for importing and exporting the Comma Separated Value (CSV)
file format used by many other programs, such as spreadsheets. Instead of the escaping
rules used by Greenplum Database standard text format, it produces and recognizes the
common CSV escaping mechanism.

The values in each record are separated by the DELIMITER character. If
the value contains the delimiter character, the QUOTE character, the
ESCAPE character (which is double quote by default), the
NULL string, a carriage return, or line feed character, then the whole
value is prefixed and suffixed by the QUOTE character. You can also use
FORCE_QUOTE to force quotes when outputting non-NULL
values in specific columns.

The CSV format has no standard way to distinguish a NULL value from an
empty string. Greenplum Database COPY handles this by quoting. A
NULL is output as the NULL parameter string and is not
quoted, while a non-NULL value matching the NULL string
is quoted. For example, with the default settings, a NULL is written as
an unquoted empty string, while an empty string data value is written with double quotes
(""). Reading values follows similar rules. You can use
FORCE_NOT_NULL to prevent NULL input comparisons for
specific columns.

Because backslash is not a special character in the CSV format,
\., the end-of-data marker, could also appear as a data value. To avoid
any misinterpretation, a \. data value appearing as a lone entry on a
line is automatically quoted on output, and on input, if quoted, is not interpreted as the
end-of-data marker. If you are loading a file created by another application that has a
single unquoted column and might have a value of \., you might need to
quote that value in the input file.

Note: In CSV format, all characters are significant. A quoted value
surrounded by white space, or any characters other than DELIMITER, will
include those characters. This can cause errors if you import data from a system that pads
CSV lines with white space out to some fixed width. If such a situation arises you might
need to preprocess the CSV file to remove the trailing white space, before importing the
data into Greenplum Database.

CSV format will both recognize and
produce CSV files with quoted values containing embedded carriage returns and line
feeds. Thus the files are not strictly one line per table row like text-format files

Note: Many programs produce strange and occasionally perverse CSV files, so the
file format is more a convention than a standard. Thus you might encounter some files that
cannot be imported using this mechanism, and COPY might produce files
that other programs cannot process.

Binary Format

The binary format option causes all data to be stored/read as binary
format rather than as text. It is somewhat faster than the text and CSV
formats, but a binary-format file is less portable across machine architectures and
Greenplum Database versions. Also, the binary format is very data type specific; for
example it will not work to output binary data from a smallint column and
read it into an integer column, even though that would work fine in text
format.

The binary file format consists of a file header, zero or more tuples containing the row data, and a file trailer. Headers and data are in network byte order.

Signature — 11-byte sequence PGCOPY\n\377\r\n\0 — note that
the zero byte is a required part of the signature. (The signature is designed to
allow easy identification of files that have been munged by a non-8-bit-clean
transfer. This signature will be changed by end-of-line-translation filters, dropped
zero bytes, dropped high bits, or parity changes.)

Flags field — 32-bit integer bit mask to denote important
aspects of the file format. Bits are numbered from 0 (LSB) to 31 (MSB). Note that
this field is stored in network byte order (most significant byte first), as are all
the integer fields used in the file format. Bits 16-31 are reserved to denote
critical file format issues; a reader should abort if it finds an unexpected bit set
in this range. Bits 0-15 are reserved to signal backwards-compatible format issues;
a reader should simply ignore any unexpected bits set in this range. Currently only
one flag is defined, and the rest must be zero (Bit 16: 1 if data has OIDs, 0 if
not).

Header extension area length — 32-bit integer, length in
bytes of remainder of header, not including self. Currently, this is zero, and the
first tuple follows immediately. Future changes to the format might allow additional
data to be present in the header. A reader should silently skip over any header
extension data it does not know what to do with. The header extension area is
envisioned to contain a sequence of self-identifying chunks. The flags field is not
intended to tell readers what is in the extension area. Specific design of header
extension contents is left for a later release.

Tuples — Each tuple begins with a 16-bit integer count of the
number of fields in the tuple. (Presently, all tuples in a table will have the same
count, but that might not always be true.) Then, repeated for each field in the tuple,
there is a 32-bit length word followed by that many bytes of field data. (The length
word does not include itself, and can be zero.) As a special case, -1 indicates a NULL
field value. No value bytes follow in the NULL case.

There is no alignment padding or
any other extra data between fields.

Presently, all data values in a
binary-format file are assumed to be in binary format (format code one). It is
anticipated that a future extension may add a header field that allows per-column
format codes to be specified.

If OIDs are included in the file, the OID field
immediately follows the field-count word. It is a normal field except that it is not
included in the field-count. In particular it has a length word — this will allow
handling of 4-byte vs. 8-byte OIDs without too much pain, and will allow OIDs to be
shown as null if that ever proves desirable.

File Trailer — The file trailer consists of a 16-bit integer word
containing -1. This is easily distinguished from a tuple's field-count
word. A reader should report an error if a field-count word is neither
-1 nor the expected number of columns. This provides an extra check
against somehow getting out of sync with the data.

Examples

Copy a table to the client using the vertical bar (|) as the field delimiter:

COPY country TO STDOUT (DELIMITER '|');

Copy data from a file into the country table:

COPY country FROM '/home/usr1/sql/country_data';

Copy into a file just the countries whose names start with 'A':

COPY (SELECT * FROM country WHERE country_name LIKE 'A%') TO
'/home/usr1/sql/a_list_countries.copy';

Copy data from a file into the sales table using single row error
isolation mode and log errors:

The content ID in the first column is the identifier inserted into the file path (for
example, gpsegdir0/gpbackup0.txt above) Files are created on the segment
hosts, rather than on the master, as they would be in a standard COPY
operation. No data files are created for the mirror segments when using ON
SEGMENT copying.

If an absolute path is specified, instead of <SEG_DATA_DIR>, such as in
the statement

COPY mytable TO '/tmp/gpdir/gpbackup_<SEGID>.txt' ON SEGMENT;

files would be placed in /tmp/gpdir on every segment. The
gpfdist tool can also be used to restore data files generated with
COPY TO with the ON SEGMENT option if redistribution is
necessary.

Note: Tools such as gpfdist can be used to restore data. The
backup/restore tools will not work with files that were manually generated with
COPY TO ON SEGMENT.

This example uses a SELECT statement to copy data to files on each
segment:

COPY (SELECT * FROM testtbl) TO '/tmp/mytst<SEGID>' ON SEGMENT;

This example copies the data from the lineitem table and uses the
PROGRAM clause to add the data to the
/tmp/lineitem_program.csv file with cat utility. The
file is placed on the Greenplum Database
master.

COPY LINEITEM TO PROGRAM 'cat > /tmp/lineitem.csv' CSV;

This example uses the PROGRAM and ON SEGMENT clauses to
copy data to files on the segment hosts. On the segment hosts, the COPY
command replaces <SEGID> with the segment content ID to create a file
for each segment instance on the segment
host.

COPY LINEITEM TO PROGRAM 'cat > /tmp/lineitem_program<SEGID>.csv' ON SEGMENT CSV;

This example uses the PROGRAM and ON SEGMENT clauses to
copy data from files on the segment hosts. The COPY command replaces
<SEGID> with the segment content ID when copying data from the files.
On the segment hosts, there must be a file for each segment instance where the file name
contains the segment content ID on the segment host.

COPY LINEITEM_4 FROM PROGRAM 'cat /tmp/lineitem_program<SEGID>.csv' ON SEGMENT CSV;

Compatibility

There is no COPY statement in the SQL standard.

The following syntax was used in earlier versions of Greenplum Database and is still
supported: